JP2006330180A - Positive photoresist composition, thick film photoresist laminated body, method for manufacturing thick film resist pattern, and method for manufacturing connecting terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive photoresist composition giving high sensitivity on forming a thick film resist pattern. <P>SOLUTION: The positive photoresist composition comprises (A) a compound which generates an acid by irradiation with active rays or radiation and (B) a resin the solubility of which is increased to alkali by an effect of an acid, wherein the component (B) contains a resin (B1) having a structural unit (b1) derived from an acrylic acid ester in which a hydrogen atom in a carboxyl group is replaced by an acid dissociating dissolution suppressing group expressed by general formula (I). In general formula (I), Y represents an alicyclic group or an alkyl group which may have a substituent; n represents 0 or an integer of 1 to 3; and each of R<SP>1</SP>and R<SP>2</SP>independently represents a hydrogen atom or a 1-5C lower alkyl group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a positive photoresist composition, a thick film photoresist laminate, a method for producing a thick film resist pattern, and a method for producing a connection terminal.

  In recent years, with the downsizing of electronic equipment, high integration of LSIs and the like has been rapidly progressing. In order to mount an LSI or the like on an electronic device, a multi-pin thin film mounting method in which connection terminals made of protruding electrodes are provided on the upper surface of a support such as a substrate is applied. In the multi-pin thin film mounting method, connection terminals made of bumps protruding from the support, connection posts made of metal posts protruding from the support, and solder balls formed thereon are used. Yes.

  For bumps and metal posts, for example, a thick photoresist layer with a thickness of about 5 μm or more is formed on the support, exposed through a predetermined mask pattern, and developed to select the part where the bumps or metal posts are to be formed. A resist pattern that has been removed (peeled) is formed, and a conductor such as copper, gold, nickel, or solder is buried in the removed portion (non-resist portion) by plating, and then the surrounding resist pattern is removed. Can be formed.

  As a thick film photoresist, a positive photosensitive resin composition having a quinonediazide group-containing compound used for forming a pump or wiring is disclosed (for example, Patent Document 1 below).

On the other hand, a chemically amplified photoresist containing an acid generator is known as a photosensitive resin composition having higher sensitivity than a conventional positive photosensitive resin composition having a quinonediazide group-containing compound. The feature of chemically amplified photoresist is that acid is generated from the acid generator by radiation irradiation (exposure), and acid diffusion is promoted by heat treatment after exposure, and it is an acid catalyst for the base resin in the resin composition. It is to cause a reaction and change its alkali solubility.
Chemically amplified photoresists are classified into a positive type in which an alkali-insoluble one becomes alkali-soluble by irradiation and a negative type in which an alkali-soluble one becomes alkali-insoluble.
For example, Patent Document 2 below discloses a positive-type chemically amplified photoresist composition for plating.
The inventors have already proposed a chemically amplified positive photoresist composition for thick films (Patent Documents 3 to 6 below).
JP 2002-258479 A JP 2001-281862 A JP 2004-309775 A JP 2004-309776 A JP 2004-309777 A JP 2004-309778 A

  In the field of such thick film photoresist compositions, the demand for higher sensitivity is increasing year by year, and even with conventional thick film chemically amplified photoresist compositions, further improvement in sensitivity is required. ing.

  The present invention has been made in view of the problems of the prior art, and is a positive photoresist composition capable of obtaining high sensitivity in the formation of a thick film resist pattern, a thick film photoresist laminate, and a thick film resist using the same. It is an object of the present invention to provide a pattern manufacturing method and a connection terminal manufacturing method.

In order to achieve the above object, the present invention employs the following configuration.
A first aspect of the present invention is a positive photoresist composition used for forming a thick film resist pattern on a support, wherein (A) a compound that generates an acid upon irradiation with actinic rays or radiation, and ( B) It contains a resin whose solubility in alkali is increased by the action of an acid, and the component (B) is a structural unit derived from an acrylate ester, and the hydrogen atom of the carboxy group is represented by the following general formula ( A positive photoresist composition comprising a resin (B1) having a structural unit (b1) substituted with an acid dissociable, dissolution inhibiting group represented by I).

[Wherein Y represents an optionally substituted aliphatic cyclic group or an alkyl group; n represents 0 or an integer of 1 to 3; and R ¹ and R ² each independently represent hydrogen. Represents an atom or a lower alkyl group having 1 to 5 carbon atoms. ]

  The second aspect of the present invention is a thick film photoresist laminate comprising a support and a thick film photoresist layer having a thickness of 10 to 150 μm comprising the positive photoresist composition of the present invention. is there.

  According to a third aspect of the present invention, there is provided a laminating step for obtaining the thick film photoresist laminate, an exposure step for selectively irradiating the thick film photoresist laminate with actinic rays or radiation, and developing and thickening after the exposing step. And a developing step for obtaining a film resist pattern.

  4th aspect of this invention includes the process of forming the connection terminal which consists of a conductor in the non-resist part of the thick film resist pattern obtained using the manufacturing method of the said thick film resist pattern, The connection terminal characterized by the above-mentioned. It is a manufacturing method.

  According to the present invention, there is provided a positive photoresist composition capable of obtaining high sensitivity in the formation of a thick film resist pattern, a thick film photoresist laminate using the same, a method of manufacturing a thick film resist pattern, and a method of manufacturing a connection terminal Is done.

Hereinafter, the present invention will be described in detail.
The “structural unit” in the claims and the specification means a monomer unit (monomer unit) constituting the resin.
The “structural unit derived from an acrylate ester” in the claims and the specification means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
The “structural unit derived from an acrylate ester” is a structural unit in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with another substituent such as a halogen atom, an alkyl group, a halogenated alkyl group, or the like. And a structural unit derived from an acrylate ester in which a hydrogen atom is bonded to a carbon atom.
In the “structural unit derived from an acrylate ester”, the term “α-position (α-position carbon atom)” means a carbon atom to which a carboxy group is bonded, unless otherwise specified.
Further, the “alkyl group” includes a linear, cyclic or branched alkyl group unless otherwise specified.

<(A) Compound that generates acid upon irradiation with active light or radiation>
The compound (A) that generates acid upon irradiation with actinic rays or radiation used in the present invention (hereinafter referred to as component (A)) is an acid generator, and is a compound that generates acid directly or indirectly by light. If there is no particular limitation.

[1] As the component (A), for example, an onium salt (A1) [hereinafter referred to as component (A1)] having a naphthalene ring in the cation portion can be used.
The cation part of the component (A1) has one or more naphthalene rings. “Having a naphthalene ring” means having a structure derived from naphthalene, and means that at least two ring structures and their aromaticity are maintained. This naphthalene ring may have a substituent such as a linear or branched alkyl group having 1 to 4 carbon atoms, a hydroxyl group, or a linear or branched alkoxy group having 1 to 4 carbon atoms. The structure derived from the naphthalene ring may be a monovalent group (one free valence) or a divalent group (two free valences) or more, but may be a monovalent group. Desirable (however, at this time, the free valence is counted excluding the portion bonded to the substituent). The number of naphthalene rings is preferably 1 to 3.

  As a cation part of (A1) component, the structure shown by the following general formula (A1) is desirable.

［式中、Ｒ^４１、Ｒ^４２、Ｒ^４３のうち少なくとも１つは下記一般式（Ａ１−０）で示される基であり、残りは炭素数１〜４の直鎖もしくは分岐鎖状のアルキル基、置換基を有していてもよいフェニル基、水酸基、または炭素数１〜４の直鎖もしくは分岐鎖状のアルコキシ基である。あるいは、Ｒ^４１、Ｒ^４２、Ｒ^４３のうちの一つが下記一般式（Ａ１−０）で示される基であり、残りの２つは、それぞれ独立して、炭素数１〜４の直鎖もしくは分岐鎖状アルキレン基であり、これらの末端が結合して環状になっていてもよい。

[Wherein, at least one of R ⁴¹ , R ⁴² and R ⁴³ is a group represented by the following general formula (A1-0), and the rest is a linear or branched alkyl group having 1 to 4 carbon atoms. , A phenyl group optionally having a substituent, a hydroxyl group, or a linear or branched alkoxy group having 1 to 4 carbon atoms. Alternatively, one of R ⁴¹ , R ⁴² and R ⁴³ is a group represented by the following general formula (A1-0), and the remaining two are each independently a straight chain having 1 to 4 carbon atoms or It is a branched alkylene group, and these ends may be bonded to form a ring.

［式中、Ｒ^５１、Ｒ^５２は、それぞれ独立して、水酸基、炭素数１〜４の直鎖もしくは分岐鎖状のアルコキシ基、または炭素数１〜４の直鎖もしくは分岐鎖状のアルキル基であり、Ｒ^５３は単結合または置換基を有していてもよい炭素数１〜４の直鎖もしくは分岐鎖状のアルキレン基であり、ｐ、ｑはそれぞれ独立して０または１〜２の整数であり、ｐ＋ｑは３以下である。ただし、Ｒ^５１が複数存在する場合、それらは相互に同じであっても異なっていてもよい。また、Ｒ^５２が複数存在する場合、それらは相互に同じであっても異なっていてもよい。］

[Wherein R ⁵¹ and R ⁵² each independently represent a hydroxyl group, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a linear or branched alkyl group having 1 to 4 carbon atoms. R ⁵³ is a single bond or a C1-C4 linear or branched alkylene group which may have a substituent, and p and q are each independently 0 or 1-2. It is an integer and p + q is 3 or less. However, when a plurality of R ⁵¹ are present, they may be the same as or different from each other. When a plurality of R ⁵² are present, they may be the same as or different from each other. ]

Of R ⁴¹ , R ⁴² and R ⁴³ , the number of groups represented by the general formula (A1-0) is preferably one from the viewpoint of the stability of the compound.

In the group represented by the general formula (A1-0), R ⁵¹ and R ⁵² are each independently a hydroxyl group, a linear or branched alkoxy group having 1 to 4 carbon atoms, or 1 to 1 carbon atoms. 4 linear or branched alkyl groups. These are desirable from the viewpoint of solubility of the component (A) in the resist composition.
p and q are each independently 0 or an integer of 1 to 2, and p + q is 3 or less.

R ⁵³ is a single bond or a linear or branched alkylene group having 1 to 4 carbon atoms which may have a substituent, and preferably a single bond. A single bond indicates that the number of carbon atoms is 0.
Examples of the substituent that the alkylene group may have include an oxygen atom (in this case, a carbonyl group is formed together with a carbon atom constituting the alkylene group), a hydroxyl group, and the like.

The rest of R ⁴¹ , R ⁴² , and R ⁴³ are a linear or branched alkyl group having 1 to 4 carbon atoms and a phenyl group that may have a substituent.
Examples of the substituent that the phenyl group may have include a hydroxyl group, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a linear or branched alkyl group having 1 to 4 carbon atoms. Can be mentioned.

One of R ⁴¹ , R ⁴² , and R ⁴³ is a group represented by the general formula (A1-0), and the other two are each independently a straight chain of 1 to 4 carbon atoms or It is a branched alkylene group, and these ends may be bonded to form a ring.
In this case, the two alkylene groups constitute a 3- to 9-membered ring including a sulfur atom. The number of atoms (including sulfur atoms) constituting the ring is preferably 5-6.

  As a suitable thing as a cation part of (A1) component, the thing shown by the following chemical formula (A1-1), (A1-2) etc. can be mentioned, for example, Especially the structure shown by chemical formula (A1-2) is mentioned. desirable.

  The component (A1) may be an iodonium salt or a sulfonium salt, but is preferably a sulfonium salt from the viewpoint of acid generation efficiency.

Accordingly, an anion capable of forming a sulfonium salt is desirable as a suitable anion moiety for the component (A1).
In particular, it is a fluoroalkyl sulfonate ion or an aryl sulfonate ion in which part or all of the hydrogen atoms are fluorinated.
The alkyl group in the fluoroalkylsulfonic acid ion may be linear, branched or cyclic having 1 to 20 carbon atoms, and preferably has 1 to 10 carbon atoms from the bulk of the acid generated and its diffusion distance. In particular, a branched or annular shape is preferable because of its short diffusion distance. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, and the like are preferable because they can be synthesized at a low cost.
The aryl group in the aryl sulfonate ion is an aryl group having 6 to 20 carbon atoms, and includes an alkyl group, a phenyl group which may or may not be substituted with a halogen atom, and a naphthyl group, and is synthesized at a low cost. Since it is possible, an aryl group having 6 to 10 carbon atoms is preferable. Specific examples include a phenyl group, a toluenesulfonyl group, an ethylphenyl group, a naphthyl group, and a methylnaphthyl group.

  In the fluoroalkyl sulfonate ion or aryl sulfonate ion, the fluorination rate when part or all of the hydrogen atoms are fluorinated is preferably 10 to 100%, more preferably 50 to 100%, In particular, those in which all hydrogen atoms are substituted with fluorine atoms are preferred because the strength of the acid is increased. Specific examples thereof include trifluoromethane sulfonate, perfluorobutane sulfonate, perfluorooctane sulfonate, and perfluorobenzene sulfonate.

  Especially, what is shown by the following general formula (A1-3) as a preferable anion part is mentioned.

In General Formula (A1-3), examples of R ⁴⁴ include structures represented by General Formula (A1-4) and General Formula (A1-5) below, and structures represented by Chemical Formula (A1-6).

［式中、ｌは１〜４の整数である。］

[Wherein, l is an integer of 1 to 4. ]

［式中、Ｒ^４５は水素原子、水酸基、炭素数１〜４の直鎖もしくは分岐鎖状のアルキル基、または炭素数１〜４の直鎖もしくは分岐鎖状のアルコキシ基を示し、ｍ’は１〜３の整数である。］

[Wherein, R ⁴⁵ represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 4 carbon atoms, and m ′ represents It is an integer of 1-3. ]

  In consideration of safety, trifluoromethanesulfonate and perfluorobutanesulfonate are preferable.

  Moreover, as an anion part, the thing of the structure containing the following nitrogen can also be used.

In formulas (A1-7) and (A1-8), X ⁰ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 carbon atoms. -6, preferably 3-5, most preferably 3 carbon atoms.
Y ⁰ and Z ⁰ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably 1-7, More preferably, it is 1-3.
The smaller the carbon number of the alkylene group of X ⁰ or the carbon number of the alkyl group of Y ⁰ and Z ⁰ , the better the solubility in the resist solvent, so that it is preferable.
In addition, in the alkylene group of X ⁰ or the alkyl group of Y ⁰ and Z ⁰ , the greater the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength, which is preferable. The proportion of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

  Moreover, what is preferable as a (A1) component is illustrated below.

  In addition to (A1), examples of the component that can be used as the component (A) include the following.

[2] For example,
2,4-bis (trichloromethyl) -6-piperonyl-1,3,5-triazine,
2,4-bis (trichloromethyl) -6- [2- (2-furyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (5-methyl-2-furyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (5-ethyl-2-furyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (5-propyl-2-furyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (3,5-dimethoxyphenyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (3,5-diethoxyphenyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (3,5-dipropoxyphenyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (3-methoxy-5-ethoxyphenyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (3-methoxy-5-propoxyphenyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- [2- (3,4-methylenedioxyphenyl) ethenyl] -s-triazine,
2,4-bis (trichloromethyl) -6- (3,4-methylenedioxyphenyl) -s-triazine,
2,4-bis-trichloromethyl-6- (3-bromo-4methoxy) phenyl-s-triazine,
2,4-bis-trichloromethyl-6- (2-bromo-4methoxy) phenyl-s-triazine,
2,4-bis-trichloromethyl-6- (2-bromo-4methoxy) styrylphenyl-s-triazine,
2,4-bis-trichloromethyl-6- (3-bromo-4methoxy) styrylphenyl-s-triazine,
2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (4-methoxynaphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- [2- (2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- [2- (5-methyl-2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- [2- (3,5-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- [2- (3,4-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (3,4-methylenedioxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, tris (1,3-dibromopropyl) -1,3,5-triazine,
A halogen-containing triazine compound such as tris (2,3-dibromopropyl) -1,3,5-triazine; and the following general formula (A2-1) such as tris (2,3-dibromopropyl) isocyanurate Halogen-containing triazine compound.

［式中、Ｒ^３〜Ｒ^５は、それぞれ同一であっても異なってもよく、ハロゲン化アルキル基を示す。］

[Wherein R ^{3 to} R ⁵ may be the same or different and each represents a halogenated alkyl group. ]

[3] For example,
α- (p-toluenesulfonyloxyimino) -phenylacetonitrile,
α- (benzenesulfonyloxyimino) -2,4-dichlorophenylacetonitrile,
α- (benzenesulfonyloxyimino) -2,6-dichlorophenylacetonitrile,
α- (2-chlorobenzenesulfonyloxyimino) -4-methoxyphenylacetonitrile,
α- (ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile,
Oxime sulfonate acid generators such as compounds represented by the following general formula (A2-2);

［式中、Ｒ^６は、一価〜三価の有機基、Ｒ^７は置換、未置換の飽和炭化水素基、不飽和炭化水素基または芳香族性化合物基を示し、ｎ’は１〜３の自然数を示す。］

[Wherein R ⁶ represents a monovalent to trivalent organic group, R ⁷ represents a substituted or unsubstituted saturated hydrocarbon group, an unsaturated hydrocarbon group or an aromatic compound group, and n ′ represents 1 to 3 The natural number of. ]

Here, the aromatic compound group refers to a group of a compound exhibiting physical and chemical properties peculiar to an aromatic compound, for example, an aromatic hydrocarbon group such as a phenyl group or a naphthyl group, a furyl group, a thienyl group. And heterocyclic groups such as These may have one or more suitable substituents on the ring, for example, a halogen atom, an alkyl group, an alkoxy group, a nitro group and the like.
R ⁷ is particularly preferably an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group.
Particularly preferred are compounds wherein R ⁶ is an aromatic compound group and R ⁷ is a lower alkyl group.

As the acid generator represented by the general formula (A2-2), when n ′ = 1, R ⁶ is any one of a phenyl group, a methylphenyl group, and a methoxyphenyl group, and R ⁷ is a methyl group. Compounds, specifically α- (methylsulfonyloxyimino) -1-phenylacetonitrile, α- (methylsulfonyloxyimino) -1- (p-methylphenyl) acetonitrile, α- (methylsulfonyloxyimino) -1- (P-methoxyphenyl) acetonitrile. When n ′ = 2, specific examples of the acid generator represented by the above general formula include an acid generator represented by the following chemical formula.

[4] For example, bis (p-toluenesulfonyl) diazomethane,
Bis (1,1-dimethylethylsulfonyl) diazomethane,
Bis (cyclohexylsulfonyl) diazomethane,
Bissulfonyldiazomethanes such as bis (2,4-dimethylphenylsulfonyl) diazomethane;
[5] For example, 2-nitrobenzyl p-toluenesulfonate,
2,6-dinitrobenzyl p-toluenesulfonate,
Nitrobenzyl derivatives such as nitrobenzyl tosylate, dinitrobenzyl tosylate, nitrobenzyl sulfonate, nitrobenzyl carbonate, dinitrobenzyl carbonate;
[6] pyrogallol trimesylate, pyrgallol tritosylate, benzyl tosylate, benzyl sulfonate,
N-methylsulfonyloxysuccinimide,
N-trichloromethylsulfonyloxysuccinimide,
N-phenylsulfonyloxymaleimide,
Sulfonic acid esters such as N-methylsulfonyloxyphthalimide;
[7] Trifluoromethanesulfonic acid esters such as N-hydroxyphthalimide and N-hydroxynaphthalimide;
[8] diphenyliodonium hexafluorophosphate,
(4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate,
Bis (p-tert-butylphenyl) iodonium trifluoromethanesulfonate,
Triphenylsulfonium hexafluorophosphate,
(4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate,
Onium salts not included in the component (A1) such as (p-tert-butylphenyl) diphenylsulfonium trifluoromethanesulfonate;
[9] Benzoin tosylate such as benzoin tosylate and α-methylbenzoin tosylate;
[10] Other diphenyliodonium salts, triphenylsulfonium salts, phenyldiazonium salts, benzyl carbonate, and the like.

Among the above-mentioned [1] to [10], oxime sulfonate acid generators such as those listed in [3] are more preferable, and among them, the following general formula (A2-3):
R′—SO ₂ O—N═C (CN) — (A2-3)
(In the formula, R ′ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms or an aryl group.)
A compound having at least two oxime sulfonate groups represented by general formula (A2-4):
_{R'-SO 2 O-N =} C (CN) -A-C (CN) = N-OSO 2 -R '... (A2-4)
Wherein A is a divalent, for example, substituted or unsubstituted alkylene group having 1 to 8 carbon atoms or an aromatic compound group, and R ′ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, for example. Group or aryl group.)
The compound represented by these is preferable.
Here, the aromatic compound group has the same meaning as the aromatic compound group as R ⁶ .
Further, in the above general formula, it is more preferable that A is a phenylene group and R ′ is, for example, a lower alkyl group having 1 to 4 carbon atoms.

As the component (A), any of the above may be used alone, or two or more may be used in combination.
The compounding amount of the component (A) in the positive photoresist composition is 0.1 to 20 parts by mass with respect to 100 parts by mass as the total mass of the component (B) and the postscript (C) component added as necessary. Preferably it is 0.2-10 mass parts. By setting it to 0.1 parts by mass or more, sufficient sensitivity can be obtained, and by setting it to 20 parts by mass or less, solubility in a solvent is good, a uniform solution is obtained, and storage stability tends to be improved. There is.

<(B) Resin whose solubility in alkali is increased by the action of acid>
The resin (hereinafter referred to as “component (B)”) whose solubility in alkali is increased by the action of acid (B) used in the chemically amplified positive photoresist composition for thick film of the present invention is derived from an acrylate ester. A resin (B1) having a structural unit (b1) in which a hydrogen atom of a carboxy group is substituted with an acid dissociable, dissolution inhibiting group represented by the general formula (I).

<Resin (B1)>
[Structural unit (b1)]
The structural unit (b1) is a structural unit derived from an acrylate ester, and an acetal group (alkoxyalkyl) is bonded to an oxygen atom at the terminal of a carbonyloxy group (—C (O) —O—) derived from a carboxy group. Group) type acid dissociable, dissolution inhibiting group [—C (R ¹ R ² ) —O— (CH ₂ ) _n —Y]. Therefore, when an acid acts, a bond is cut between the acid dissociable, dissolution inhibiting group and the terminal oxygen atom.
Since the component (B) contains the resin (B1) having the structural unit (b1) having such an acid dissociable, dissolution inhibiting group, it is insoluble in alkali before exposure and is generated from the component (A) by exposure. When the acid acts, the acid dissociable, dissolution inhibiting group is dissociated, thereby increasing the alkali solubility of the entire component (B) that was insoluble in alkali. Therefore, in the formation of a resist pattern, when selective exposure is performed on the resist, or when post-exposure heating (PEB) is performed in addition to exposure, the exposed portion turns into alkali-soluble while the unexposed portion is alkali-insoluble. Thus, a positive resist pattern can be formed by alkali development.

In the general formula ^(I), representative of R 1, ^{R 2} are each independently a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. Preferable examples of the lower alkyl group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. Industrially, a methyl group is preferable.
At least one of R ¹ and R ² is preferably a hydrogen atom, more preferably a hydrogen atom.
In general formula (I), n represents 0 or an integer of 1 to 3. Preferably n is 0 or 1, more preferably 0.

In general formula (I), Y is an aliphatic cyclic group or an alkyl group, and the aliphatic cyclic group may or may not have a substituent on its ring skeleton. Y is preferably an aliphatic cyclic group which may have a substituent.
Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity. The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” in the present invention is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but may be a hydrocarbon group. preferable. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. A polycyclic group is preferred.

Specific examples of such aliphatic cyclic groups include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. .
Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
Y is particularly preferably a group obtained by removing one or more hydrogen atoms from adamantane (which may further have a substituent).
When the aliphatic cyclic group as Y has a substituent on the ring skeleton, examples of the substituent include polar groups such as a hydroxyl group, a carboxy group, a cyano group, and an oxygen atom (= O), and the number of carbon atoms. 1-4 linear or branched lower alkyl groups may be mentioned. When it has a substituent on the ring skeleton, it preferably has the polar group and / or the lower alkyl group. As the polar group, an oxygen atom (═O) is particularly preferable.

The alkyl group as Y is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 6 to 15 carbon atoms.
When Y is an alkyl group, preferred examples of the alkoxyalkyl group (chain-like) represented by formula (I) include 1-methoxyethyl group, 1-ethoxyethyl group, 1-n-propoxyethyl group, 1- iso-propoxyethyl group, 1-n-butoxyethyl group, 1-iso-butoxyethyl group, 1-tert-butoxyethyl group, 1-methoxypropyl group, 1-ethoxypropyl group, 1-methoxy-1-methyl- Examples thereof include an ethyl group and a 1-ethoxy-1-methyl-ethyl group. Moreover, since the alkyl group which is Y is a long chain, since plating tolerance is provided, it is preferable.

  Preferable examples of the structural unit (b1) include a structural unit represented by the following general formula (b1-01) and a structural unit represented by the following general formula (b1-02).

[In the above formula, Y represents an optionally substituted aliphatic cyclic group or an alkyl group; n represents 0 or an integer of 1 to 3; m represents 0 or 1; Independently represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated lower alkyl group having 1 to 5 carbon atoms; R ¹ and R ² each independently represent a hydrogen atom or 1 to carbon atoms; 5 represents a lower alkyl group. ]

In general formulas (b1-01) and (b1-02), R represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated lower alkyl group having 1 to 5 carbon atoms.
The fluorinated lower alkyl group is a group in which part or all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms, and any of them may be used, but it is preferable that all are fluorinated.
Preferable examples of the lower alkyl group as R include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. Industrially, a methyl group is preferable.
The fluorinated lower alkyl group having 1 to 5 carbon atoms is preferably a trifluoromethyl group, a hexafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, or the like, and more preferably a trifluoromethyl group.

In the general formulas (b1-01) and (b1-02), Y, n, R ¹ and R ² are the same as those in the general formula (I).
Specific examples of the structural unit represented by the general formula (b1-01) are shown below.

In formulas (b1-01-17) to (b1-01-28), R ³¹ represents a linear or branched alkyl group having 1 to 4 carbon atoms, a hydroxyl group, or a CN group, and n ″ is 1 to 3. Indicates an integer.

  Specific examples of the structural unit represented by the general formula (b1-02) are shown below.

  The structural unit (b1) may include any one selected from the group consisting of the structural unit represented by the general formula (b1-01) and the structural unit represented by the general formula (b1-02). Moreover, 2 or more types may be included.

  The proportion of the structural unit (b1) in the resin (B1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, further preferably 25 to 60 mol%, based on all structural units of the resin (B1). preferable. By setting it to the lower limit value or more, a good resist pattern can be obtained when the resist composition is used, and by setting it to the upper limit value or less, a balance with other structural units can be achieved.

[Structural unit (b2)]
Furthermore, the resin (B1) is preferably a resin made of a copolymer containing a structural unit (b2) derived from a polymerizable compound having an ether bond in addition to the structural unit (b1). By including the structural unit (b2), the adhesion to the substrate during development and the plating solution resistance are improved.

  The structural unit (b2) is a structural unit derived from a polymerizable compound having an ether bond. Examples of the polymerizable compound having an ether bond include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, and ethyl carbitol. Radical polymerizable compounds such as (meth) acrylic acid derivatives having an ether bond and an ester bond such as (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate Examples thereof include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, and methoxytriethylene glycol (meth) acrylate.These compounds can be used alone or in combination of two or more.

  When the resin (B1) has the structural unit (b2), the proportion of the structural unit (b2) in the resin (B1) is preferably 5 to 80 mol% with respect to the total structural units of the resin (B1). 60 mol% is more preferable and 10-50 mol% is further more preferable. By setting the proportion of the structural unit (b2) to be equal to or lower than the upper limit value of the above range, it is possible to suppress a decrease in the remaining film ratio. Can be improved.

[Structural unit (b3)]
The resin (B1) may further have a structural unit (b3) represented by the following general formula (b3-0) as long as the effects of the present invention are not impaired.

［式中、Ｒ^３２は水素原子又はメチル基、Ｒ^３３は低級アルキル基を示し、Ｘはそれが結合している炭素原子と共に炭素数５乃至２０の炭化水素環を形成する。］

[Wherein R ³² represents a hydrogen atom or a methyl group, R ³³ represents a lower alkyl group, and X forms a hydrocarbon ring having 5 to 20 carbon atoms together with the carbon atom to which it is bonded. ]

The lower alkyl group represented by R ³³ may be linear or branched, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and isobutyl. Group, sec-butyl group, tert-butyl group, various pentyl groups and the like. Among these, lower alkyl groups having 2 to 4 carbon atoms are preferable from the viewpoints of high contrast, good resolution, depth of focus, and the like.

X forms a monocyclic or polycyclic hydrocarbon ring having 5 to 20 carbon atoms together with the carbon atom to which it is bonded.
Examples of monocyclic hydrocarbon rings include cyclopentane, cyclohexane, cycloheptane, cyclooctane and the like.
Examples of the polycyclic hydrocarbon ring include a bicyclic hydrocarbon ring, a tricyclic hydrocarbon ring, and a tetracyclic hydrocarbon ring. Specific examples include polycyclic hydrocarbon rings such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
Of the above, a cyclohexane ring and an adamantane ring are preferred as the hydrocarbon ring having 5 to 20 carbon atoms formed by X together with the carbon atom to which it is bonded.

  Preferable specific examples of the structural unit (b3) include those represented by the following general formulas (b3-1), (b3-2), and (b3-3).

  As the structural unit (b3), one type of structural units represented by the general formula (b3-0) may be used, but two or more types of structural units having different structures may be used.

  When the resin (B1) has the structural unit (b3), the proportion of the structural unit (b3) in the resin (B1) is preferably 0 to 50 mol% with respect to all the structural units of the resin (B1). The acid diffusion length can be controlled by setting the proportion of the structural unit (b3) to be equal to or less than the upper limit of the above range.

[Other polymerizable compounds]
Furthermore, the resin (B1) can contain other polymerizable compounds as monomers for the purpose of appropriately controlling physical and chemical properties. Here, the “other polymerizable compound” means a polymerizable compound as a structural unit other than the structural unit (b1), the structural unit (b2), and the structural unit (b3).
Examples of such polymerizable compounds include known radically polymerizable compounds and anionic polymerizable compounds.
For example, monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl Radically polymerizable compounds such as methacrylic acid derivatives having a carboxyl group and an ester bond such as phthalic acid and 2-methacryloyloxyethyl hexahydrophthalic acid;
(Meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate;
(Meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate;
(Meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate;
Dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate;
Vinyl group-containing aromatic compounds such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, α-ethylhydroxystyrene;
Vinyl group-containing aliphatic compounds such as vinyl acetate;
Conjugated diolefins such as butadiene and isoprene;
Nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile;
Chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride;
Examples thereof include polymerizable compounds containing amide bonds such as acrylamide and methacrylamide.

  The polystyrene-converted mass average molecular weight (hereinafter referred to as mass average molecular weight) of the resin (B1) is preferably 10,000 to 500,000, more preferably 20,000 to 400,000. When the mass average molecular weight is less than or equal to the upper limit value in the above range, a decrease in peelability can be suppressed, and when the mass average molecular weight is greater than or equal to the lower limit value in the above range, sufficient strength of the resist film is obtained. In addition, it is possible to suppress the tendency to cause profile swelling and cracking during plating.

  Furthermore, the resin (B1) preferably has a dispersity of 1.05 or more. Here, the degree of dispersion is a value obtained by dividing the mass average molecular weight by the number average molecular weight. When the degree of dispersion is 1.05 or more, stress resistance to plating is weakened, and the tendency of the metal layer obtained by plating to easily swell can be suppressed.

<Resin (B2)>
100% of the component (B) may be the resin (B1), but the resin (B1) and a copolymer having a structural unit (b4) represented by the following general formula (b4-1) It may be a mixed resin containing the resin (B2).

［式中、Ｒ^１１は水素原子又はメチル基、Ｒ^１２は酸不安定基を示す。］

[Wherein, R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents an acid labile group. ]

The acid labile group of R ¹² is variously selected, and is particularly a group represented by the following formula (b4-2) or (b4-3), a linear, branched or cyclic group having 1 to 6 carbon atoms. An alkyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, or a trialkylsilyl group is preferable.

［式中、Ｒ^１８、Ｒ^１９はそれぞれ独立して水素原子又は炭素数１〜６の直鎖状又は分岐状のアルキル基であり、Ｒ^２０は炭素数１〜１０の直鎖状、分岐状又は環状のアルキル基である。また、Ｒ^２１は炭素数１〜６の直鎖状、分岐状又は環状のアルキル基であり、ａは０又は１である。］

[Wherein R ¹⁸ and R ¹⁹ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ²⁰ is a linear or branched group having 1 to 10 carbon atoms. Or it is a cyclic alkyl group. R ²¹ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, and a is 0 or 1. ]

  Examples of linear and branched alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, etc. Can be exemplified by a cyclohexyl group and the like.

Here, as a specific example of the acid labile group represented by the formula (b4-2), a specific example of an alkoxyalkyl group (chain-like) in the case where Y is an alkyl group in the general formula (I) The same thing is mentioned.
Specific examples of the acid labile group of the above formula (b4-3) include a tert-butoxycarbonyl group and a tert-butoxycarbonylmethyl group.
Specific examples of the trialkylsilyl group include those having 1 to 6 carbon atoms in each alkyl group such as a trimethylsilyl group and a tri-tert-butyldimethylsilyl group.

As the structural unit (b4), one type of structural units represented by the general formula (b4-1) may be used, but two or more types of structural units having different structures may be used.
As for the content rate of the structural unit (b4) in resin (B2), 5-95 mass% is preferable with respect to all the structural units of resin (B2), More preferably, 10-90 mass% is preferable. Sensitivity can be improved as it is 95 mass% or less, and the fall of the remaining film rate can be suppressed by setting it as 5 mass% or more.

  Furthermore, the resin (B2) can contain other polymerizable compounds as monomers for the purpose of appropriately controlling physical and chemical properties. Here, the “other polymerizable compound” means a polymerizable compound other than the structural unit (b4). Specific examples of such polymerizable compounds include those similar to the examples of “other polymerizable compounds” that can be contained in the resin (B1).

<(C) Alkali-soluble resin>
The positive photoresist composition of the present invention preferably contains (C) an alkali-soluble resin [referred to as component (C)].
As the component (C), an arbitrary one can be appropriately selected from known alkali-soluble resins in conventional chemically amplified photoresists.
Among these, in particular, at least one resin selected from (c1) a novolak resin, (c2) a copolymer having a hydroxystyrene structural unit and a styrene structural unit, (c3) an acrylic resin, and (c4) a vinyl resin. And (c1) a novolak resin and / or (c2) a copolymer of a hydroxystyrene structural unit and a styrene structural unit. This is because it is easy to control the coating property and the development speed.

[(C1) Novolac resin]
The novolak resin as component (c1) can be obtained, for example, by addition condensation of an aromatic compound having a phenolic hydroxyl group (hereinafter simply referred to as “phenols”) and an aldehyde in the presence of an acid catalyst.
In this case, examples of phenols used include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p -Butylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3, 4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, phlorogricinol, hydroxydiphenyl, bisphenol A, gallic acid, gallic acid ester, α-naphthol, β-naphthol, etc. The
Examples of aldehydes include formaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, and acetaldehyde.

The catalyst for the addition condensation reaction is not particularly limited. For example, hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid and the like are used as the acid catalyst.
In particular, a novolak resin using only m-cresol as a phenol is preferable because the development profile is particularly good.

[(C2) Copolymer having hydroxystyrene structural unit and styrene structural unit]
The component (c2) is a copolymer having at least a hydroxystyrene structural unit and a styrene structural unit. That is, it is a copolymer composed of a hydroxystyrene structural unit and a styrene structural unit, or a copolymer composed of a hydroxystyrene structural unit, a styrene structural unit and other structural units.

Examples of the hydroxystyrene structural unit include hydroxystyrene structural units such as hydroxystyrene such as p-hydroxystyrene, and α-alkylhydroxystyrene such as α-methylhydroxystyrene and α-ethylhydroxystyrene.
Examples of the styrene structural unit include styrene, chlorostyrene, chloromethylstyrene, vinyltoluene, α-methylstyrene, and the like.

[(C3) Acrylic resin]
The acrylic resin as the component (c3) is not particularly limited as long as it is an alkali-soluble acrylic resin. In particular, it is derived from a structural unit derived from a polymerizable compound having an ether bond and a polymerizable compound having a carboxyl group. Those containing different structural units are preferred.
Examples of the polymerizable compound having an ether bond include 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxy polyethylene glycol (meta ), (Meth) acrylic acid derivatives having an ether bond and an ester bond such as methoxypolypropylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, etc., preferably 2-methoxyethyl acrylate, Methoxytriethylene glycol acrylate. These compounds can be used alone or in combination of two or more.

  Examples of the polymerizable compound having a carboxyl group include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, 2-methacryloyloxyethyl succinic acid, and 2-methacryloyloxyethyl. Examples include maleic acid, 2-methacryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid and other compounds having a carboxyl group and an ester bond, and acrylic acid and methacrylic acid are preferred. These compounds can be used alone or in combination of two or more.

[(C4) Vinyl resin]
The vinyl resin as the component (c4) is poly (vinyl lower alkyl ether), and is obtained by polymerizing a single or a mixture of two or more vinyl lower alkyl ethers represented by the following general formula (C1) ( Co) polymer.

［式中、Ｒ^８ は炭素数１〜５の直鎖状もしくは分岐状のアルキル基を示す。］

[Wherein, R ⁸ represents a linear or branched alkyl group having 1 to 5 carbon atoms. ]

  In the general formula (C1), examples of the linear or branched alkyl group having 1 to 5 carbon atoms include a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i- A butyl group, n-pentyl group, i-pentyl group, etc. can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, and an i-butyl group are preferable, and a methyl group is particularly preferable. In the present invention, a particularly preferred poly (vinyl lower alkyl ether) is poly (vinyl methyl ether).

  The blending amount of the component (C) is 5 to 95 parts by mass, preferably 10 to 90 parts by mass with respect to 100 parts by mass of the total mass of the component (B) and the component (C). By setting it to 5 parts by mass or more, crack resistance can be improved, and by setting it to 95 parts by mass or less, there is a tendency that film loss during development can be prevented.

<(D) Acid diffusion controller>
The positive photoresist composition of the present invention further comprises (D) an acid diffusion controller [hereinafter referred to as (D) component] in order to improve the resist pattern shape, the stability of standing, and the like. It is preferable to contain.
As the component (D), an arbitrary one can be appropriately selected from those known as acid diffusion control agents in conventional chemically amplified photoresists. In particular, (d1) a nitrogen-containing compound is preferably contained, and (d2) an organic carboxylic acid or an oxo acid of phosphorus or a derivative thereof can be further contained as necessary.

[(D1) Nitrogen-containing compound]
Examples of the nitrogen-containing compound as component (d1) include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tribenzylamine, diethanolamine, triethanolamine, n-hexylamine, n -Heptylamine, n-octylamine, n-nonylamine, ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'- Diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethyla Toamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, imidazole Benzimidazole, 4-methylimidazole, 8-oxyquinoline, acridine, purine, pyrrolidine, piperidine, 2,4,6-tri (2-pyridyl) -S-triazine, morpholine, 4-methylmorpholine, piperazine, 1, 4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like can be mentioned.
Of these, alkanolamines such as triethanolamine are particularly preferred.
These may be used alone or in combination of two or more.
The component (d1) is usually used in the range of 0 to 5 parts by mass, particularly in the range of 0 to 3 parts by mass, with respect to 100 parts by mass of the total mass of the component (B) and the optional component (C). Is preferred.

[(D2) Organic carboxylic acid or phosphorus oxo acid or derivative thereof]
As the organic carboxylic acid, for example, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are preferable, and salicylic acid is particularly preferable.
Phosphorus oxoacids or derivatives thereof include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester and other phosphoric acid or derivatives thereof such as phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid- Like phosphonic acids such as di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester and derivatives thereof, phosphinic acids such as phosphinic acid, phenylphosphinic acid and their esters Among these, phosphonic acid is particularly preferable.
These may be used alone or in combination of two or more.
The component (d2) is usually used in the range of 0 to 5 parts by mass, particularly in the range of 0 to 3 parts by mass, with respect to 100 parts by mass of the total mass of the component (B) and the optional (C) component. It is preferable.
The component (d2) is preferably used in the same amount as the component (d1). This is because the component (d2) and the component (d1) form a salt and stabilize.

<Other ingredients>
The positive photoresist composition of the present invention contains, as desired, additional miscible additives such as additional resins, plasticizers, adhesion promoters for improving the performance of the resist film as long as the essential characteristics are not impaired. Conventional agents such as an agent, a stabilizer, a colorant, and a surfactant can be added and contained.

<Organic solvent>
Moreover, an organic solvent can be suitably mix | blended with a positive photoresist composition for viscosity adjustment.
Specific examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, Polyhydric alcohols and their derivatives such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether of dipropylene glycol or dipropylene glycol monoacetate; cyclic ethers such as dioxane; and methyl lactate, Ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methoxypropion Include methyl, esters such as ethyl ethoxypropionate. These may be used alone or in combination of two or more.

  For example, in order to obtain a film thickness of preferably 10 μm or more by using a spin coating method, the amount of these solvents used is such that the solid content concentration in the positive photoresist composition is within a range from 30 mass% to 65 mass%. It is preferable to do. When the solid content concentration is less than 30% by mass, it is difficult to obtain a thick film suitable for the production of connection terminals. When the solid content concentration exceeds 65% by mass, the fluidity of the composition is remarkably deteriorated and the handling is difficult. In the spin coating method, it is difficult to obtain a uniform resist film.

  The positive photoresist composition can be prepared, for example, by mixing and stirring the above-mentioned components by a usual method, and if necessary, may be dispersed and mixed using a disperser such as a dissolver, a homogenizer, or a three-roll mill. . Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

  The positive photoresist composition of the present invention is suitable for forming a thick photoresist layer having a thickness of 10 to 150 μm, more preferably 20 to 120 μm, and still more preferably 20 to 80 μm on a support.

<Thick film photoresist laminate>
The thick film photoresist laminate of the present invention is formed by laminating a thick film photoresist layer made of the positive photoresist composition of the present invention on a support.
The support is not particularly limited, and a conventionally known one can be used. Examples thereof include a substrate for electronic parts and a substrate on which a predetermined wiring pattern is formed. Examples of the substrate include a metal substrate such as silicon, silicon nitride, titanium, tantalum, palladium, titanium tungsten, copper, chromium, iron, aluminum, gold, and nickel, and a glass substrate. As a material for the wiring pattern, for example, copper, solder, chromium, aluminum, nickel, gold, or the like is used.
In the positive photoresist composition of the present invention, even if the material of the surface on which the photoresist layer is formed is the above-mentioned material, for example, the trailing phenomenon at the interface between the pattern and the substrate hardly occurs, and the perpendicularity of the shape An excellent resist pattern can be obtained.

The thick film photoresist laminate can be manufactured, for example, as follows.
That is, a desired coating film is formed by applying a solution of the positive photoresist composition prepared as described above onto a support and removing the solvent by heating. As a coating method on a to-be-processed support body, methods, such as a spin coat method, a slit coat method, a roll coat method, a screen printing method, an applicator method, are employable. The pre-baking conditions for the coating film of the composition of the present invention vary depending on the type of each component in the composition, the blending ratio, the coating film thickness, etc., but are usually 70 to 150 ° C., preferably 80 to 140 ° C. ~ About 60 minutes.

  The thickness of the thick photoresist layer is 10 to 150 μm, preferably 20 to 120 μm, more preferably 20 to 80 μm.

<Resist pattern formation method>
In order to form a resist pattern using the thick film photoresist laminate thus obtained, an actinic ray or radiation, for example, having a wavelength of 300, is applied to the obtained thick film photoresist layer through a mask having a predetermined pattern. Irradiation (exposure) selectively with ultraviolet light or visible light of ˜500 nm. In the exposed portion, the alkali solubility of the thick photoresist layer changes.
Here, the actinic ray means a ray that activates the acid generator in order to generate an acid. As a radiation source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used. Here, the radiation means ultraviolet rays, visible rays, far ultraviolet rays, X-rays, electron beams, ion rays, and the like. The amount of radiation irradiation varies depending on the type of each component in the composition, the blending amount, the film thickness of the coating film, and the like, but, for example, when using an ultrahigh pressure mercury lamp, 100 to 10,000 mJ / cm ² is preferable.

Then, after the exposure, development processing is performed. It is preferable that after the exposure and before the development processing, heat (PEB) treatment is performed to promote acid diffusion.
The positive photoresist composition of the present invention can be subjected to PEB treatment under mild conditions. For example, acid diffusion can be promoted by heat treatment at 70 to 120 ° C. for about 1 to 10 minutes. Moreover, a thick film resist pattern can be formed even if development processing is performed after heating for about 30 to 300 minutes at room temperature after exposure.

In the development process, for example, a predetermined alkaline aqueous solution is used as a developer, and unnecessary portions are dissolved and removed to obtain a predetermined resist pattern. Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethyl. Ethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo [4,3,0 An aqueous solution of an alkali such as -5-nonane can be used. Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the alkaline aqueous solution can also be used as a developer.
The development time varies depending on the type of each component of the composition, the blending ratio, and the dry film thickness of the composition, but it is usually 1 to 30 minutes, and the development method is a liquid piling method, dipping method, paddle method, spray development method. Any of these may be used. After the development, washing with running water is performed for 30 to 90 seconds and dried using an air gun or an oven.

Then, a connection terminal such as a metal post or a bump is formed by embedding a conductor such as metal in the non-resist portion (the portion removed with the alkaline developer) of the resist pattern thus obtained, for example, by plating or the like. can do. The plating method is not particularly limited, and various conventionally known methods can be employed. As the plating solution, solder plating, copper plating, gold plating, or nickel plating solution is particularly preferably used.
The remaining resist pattern is finally removed using a stripping solution or the like according to a conventional method.

ADVANTAGE OF THE INVENTION According to this invention, the positive photoresist composition which can obtain high sensitivity in formation of a thick film resist pattern, the thick film photoresist laminated body using the same, the manufacturing method of a thick film resist pattern, and the manufacturing method of a connection terminal are obtained. It is done. As will be shown in the following examples, according to the present invention, improvement in sensitivity is achieved without impairing main characteristics such as compatibility (dispersion stability), coatability, development and resolution of the positive photoresist composition. can do. Moreover, it is excellent also in the perpendicularity of the thick film resist pattern shape.
A good resist pattern can be formed even if the material of the surface on which the photoresist layer is formed is not only silicon but also a metal surface such as copper, aluminum, nickel, gold or the like. This is an important and advantageous effect in a positive photoresist composition used for a thick film.

(Examples 1-4, Comparative Examples 1 and 2)
Each component shown in Table 1 below was mixed with propylene glycol monomethyl ether acetate to form a uniform solution (solid content concentration 50% by mass), followed by filtration through a membrane filter having a pore size of 1 μm to obtain a positive photoresist composition. In addition, the unit of the compounding quantity shown in Table 1 is a mass part.

Each component in Table 1 is as follows.
(A-1): an onium salt-based acid generator having a naphthalene ring in the cation moiety, component (A1) represented by the above chemical formula (A1-9).

(B-1): As the structural unit (b1), 55 mol% of 1- (2-adamantyloxy) ethyl methacrylate unit represented by the above chemical formula (b1-01-3), and 2 as the structural unit (b2) A copolymer having a mass average molecular weight (Mw) of 30,000, comprising 30 mol% of ethoxyethyl acrylate units, 10 mol% of n-butyl acrylate units and 5 mol% of acrylic acid units as other polymerizable compounds.
(B-2): A copolymer obtained by changing Mw to 100000 in (B-1).
(B-3): In (B-1), the structural unit (b1) is a 1- (4-oxo-2-adamantyloxy) ethyl methacrylate unit 55 represented by the chemical formula (b1-01-17). Copolymer with Mw 30000 replaced by mol%.
(B-4): A copolymer obtained by changing Mw to 100000 in (B-3).
(B-5): 30 mol% of 2-ethoxyethyl acrylate units as the structural unit (b2), 55 mol% of 1-methylcyclohexyl methacrylate units as the structural unit (b3), and 10 n-butyl acrylate units as the other polymerizable compounds. A copolymer having a mass average molecular weight (Mw) of 300,000 consisting of mol% and acrylic acid units of 5 mol%.
(B-6): A copolymer of Mw 100000 in which the structural unit (b3) is replaced with 55 mol% of 2-methyl-2-adamantyl methacrylate unit represented by the following chemical formula (1) in (B-5).

(C-1): Copolymer comprising 10% by mole of hydroxystyrene units and 90% of styrene units (C-2): Novolak resin (D-1): Triethanolamine (D-2): Salicylic acid

[Test example]
The following characteristics evaluation was performed on the positive photoresist compositions produced in the above-mentioned Examples and Comparative Examples. The results are shown in Table 2 below.
(1) Compatibility (dispersion stability)
The positive photoresist composition was stirred at room temperature for 12 hours, the dissolved state (dispersed state) immediately after stirring and 12 hours after stirring was visually observed, and judged according to the following evaluation criteria.
◯: It was visually confirmed that the composition was uniformly dispersed immediately after stirring for 12 hours.
Δ: The composition was uniformly dispersed immediately after stirring for 12 hours, but phase separation was allowed to stand for 12 hours after stirring.
X: The composition is not uniformly dispersed immediately after stirring for 12 hours.

(2) Coating property Each composition was coated on a 5-inch gold sputtering wafer (gold substrate) using a spinner for 25 seconds at 1000 rpm, and then pre-baked on a hot plate at 130 ° C. for 6 minutes to a film thickness of 20 μm. A thick film photoresist laminate was obtained.
In addition, a coating film having a thickness of 100 μm was formed by changing the conditions. Specifically, each composition was applied on a 5-inch gold sputtering wafer using a spinner at 500 rpm for 10 seconds and then pre-baked on a hot plate at 120 ° C. for 60 minutes to form a coating film having a thickness of 100 μm. A thick film photoresist laminate was obtained.

The formed coating film was visually observed and applicability was determined according to the following evaluation criteria.
◯: The obtained coating film is uniform and uniform.
(Triangle | delta): The flatness of the obtained coating film is bad and is not uniform.
X: The obtained coating film has unevenness such as pinholes and repellency.

(3) Development / Resolvability Each thick film photoresist laminate formed in the same manner as in the above-described coating property test, using an aligner (trade name: PLA501F, manufactured by Canon), through a pattern mask for resolution measurement. , UV exposure was performed stepwise in the range of 100 to 10,000 mJ / cm ² , respectively. After exposure, the film was heated (PEB) at 80 ° C. for 5 minutes, and then developed with a developer (trade name: PMER series, P-7G, manufactured by Tokyo Ohka Kogyo Co., Ltd.).
Thereafter, it was washed with running water and blown with nitrogen to obtain a patterned cured product. This was observed with a microscope, and development / resolution was judged according to the following evaluation criteria.
Moreover, regarding the compositions of Examples 1 to 4, a patterned cured product was formed in the same manner using four types of sputtering wafers of 5 inches of Si, Cu, Ni, and Al. A pattern-like cured product was obtained on any substrate.
◯: A pattern having an aspect ratio of 2 or more is formed with any of the above exposure amounts, and no residue is observed.
X: A pattern having an aspect ratio of less than 2 is not formed or a residue is observed.
The aspect ratio is a value of (resist height on the pattern / resist width on the pattern).

(4) Sensitivity (photosensitivity)
Using a positive photoresist composition on a 5-inch Si or Au, Cu, Ni, Al sputtering wafer, two types of film thicknesses (20 μm and 100 μm) are formed, respectively. Through the mask, division exposure was performed in the range of 100 to 10,000 mJ / cm ² using an aligner (trade name: PLA501F, manufactured by Canon). After exposure, the film was heated (PEB) at 80 ° C. for 5 minutes, and then developed with a developer (trade name PMER series, P-7G, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, it was washed with running water and blown with nitrogen to obtain a patterned cured product.
This is observed with a microscope, a pattern with an aspect ratio of 2 or more is formed, the exposure amount at which no residue is observed, that is, the minimum exposure amount necessary to form the pattern is measured, and the sensitivity (photosensitivity) is as follows. Judgment was made according to the evaluation criteria.

<When the film thickness is 20 μm>
◯: The minimum exposure necessary for pattern formation is 300 mJ / cm ² or less.
△: The minimum exposure amount necessary for pattern formation 300 mJ / cm ² greater, less than 600 mJ / cm ^2.
X: The minimum exposure required for pattern formation is 600 mJ / cm ² or more.
<When film thickness is 100 μm>
○: The minimum exposure necessary for pattern formation is 2500 mJ / cm ² or less.
△: The minimum exposure amount necessary for pattern formation 2,500 mJ / cm ² greater, less than 5000 mJ / cm ^2.
X: The minimum exposure required for pattern formation is 5000 mJ / cm ² or more.

(5) Verticalness of pattern shape In the development / resolution test, the cross-sectional shape of the formed resist pattern was observed with a cross-sectional SEM.
As a result, the resist patterns obtained in Examples 1 to 4 and Comparative Examples 1 and 2 all had good pattern perpendicularity (rectangular cross section).

As shown in the results of the above test examples, the positive photoresist compositions of the examples have improved sensitivity without impairing compatibility (dispersion stability), coatability, development / resolution, and shape. It is possible to form a resist pattern having excellent verticality.

Claims (7)

A positive photoresist composition used to form a thick film resist pattern on a support,
(A) a compound that generates an acid upon irradiation with actinic rays or radiation, and (B) a resin whose solubility in alkali is increased by the action of the acid,
The component (B) is a structural unit derived from an acrylate ester, in which a hydrogen atom of a carboxy group is substituted with an acid dissociable, dissolution inhibiting group represented by the following general formula (I) ( A positive photoresist composition comprising a resin (B1) having b1).

[Wherein Y represents an optionally substituted aliphatic cyclic group or an alkyl group; n represents 0 or an integer of 1 to 3; and R ¹ and R ² each independently represent hydrogen. Represents an atom or a lower alkyl group having 1 to 5 carbon atoms. ] The structural unit (b1) is a structural unit represented by the following general formula (b1-01) and a structural unit represented by the following general formula (b1-02)

[In the above formula, Y represents an optionally substituted aliphatic cyclic group or an alkyl group; n represents 0 or an integer of 1 to 3; m represents 0 or 1; Independently represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated lower alkyl group having 1 to 5 carbon atoms; R ¹ and R ² each independently represent a hydrogen atom or 1 to carbon atoms; 5 represents a lower alkyl group. ]
The positive photoresist composition according to claim 1, comprising at least one selected from the group consisting of:   The positive photoresist composition according to claim 1, further comprising (C) an alkali-soluble resin.   The positive photoresist composition according to claim 1, further comprising (D) an acid diffusion controller.   A thick film photoresist laminate comprising a support and a thick film photoresist layer having a thickness of 10 to 150 μm made of the positive photoresist composition according to claim 1.   A lamination process for obtaining the thick film photoresist laminate according to claim 5, an exposure process for selectively irradiating the thick film photoresist laminate with actinic rays or radiation, and development after the exposure process to develop a thick film resist pattern And a developing step for obtaining a thick film resist pattern. A method for producing a connection terminal, comprising a step of forming a connection terminal made of a conductor in a non-resist portion of a thick film resist pattern obtained by using the method for producing a thick film resist pattern according to claim 6.